extended man page to mention number of visible windows

dwm.1

@@ -19,14 +19,15 @@ layout applied.
 Windows are grouped by tags. Each window can be tagged with one or multiple
 tags. Selecting certain tags displays all windows with these tags.
 .P
-Each screen contains a small status bar which displays all available tags, the layout,
+Each screen contains a small status bar which displays all available tags, the
-the title of the focused window, and the text read from the root window name
+layout, the number of visible windows, the title of the focused window, and the
-property, if the screen is focused. A floating window is indicated with an
+text read from the root window name property, if the screen is focused. A
-empty square and a maximised floating window is indicated with a filled square
+floating window is indicated with an empty square and a maximised floating
-before the windows title.  The selected tags are indicated with a different
+window is indicated with a filled square before the windows title.  The
-color. The tags of the focused window are indicated with a filled square in the
+selected tags are indicated with a different color. The tags of the focused
-top left corner.  The tags which are applied to one or more windows are
+window are indicated with a filled square in the top left corner.  The tags
-indicated with an empty square in the top left corner.
+which are applied to one or more windows are indicated with an empty square in
+the top left corner.
 .P
 dwm draws a small border around windows to indicate the focus state.
 .SH OPTIONS